Ultrasound-Based Fluid-Structure Interaction Modeling of Abdominal Aortic Aneurysms Incorporating Pre-stress

Judith H C Fonken; Esther J Maas; Arjet H M Nievergeld; Marc R H M van Sambeek; Frans N van de Vosse; Richard G P Lopata

doi:10.3389/fphys.2021.717593

Ultrasound-Based Fluid-Structure Interaction Modeling of Abdominal Aortic Aneurysms Incorporating Pre-stress

Front Physiol. 2021 Aug 13:12:717593. doi: 10.3389/fphys.2021.717593. eCollection 2021.

Authors

Judith H C Fonken^{1

2}, Esther J Maas^{1

2}, Arjet H M Nievergeld^{1

2}, Marc R H M van Sambeek^{1

2}, Frans N van de Vosse³, Richard G P Lopata¹

Affiliations

¹ Photoacoustics & Ultrasound Laboratory Eindhoven (PULS/e), Department of Biomechanical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands.
² Department of Vascular Surgery, Catharina Hospital Eindhoven, Eindhoven, Netherlands.
³ Cardiovascular Biomechanics, Department of Biomechanical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands.

Abstract

Currently, the prediction of rupture risk in abdominal aortic aneurysms (AAAs) solely relies on maximum diameter. However, wall mechanics and hemodynamics have shown to provide better risk indicators. Patient-specific fluid-structure interaction (FSI) simulations based on a non-invasive image modality are required to establish a patient-specific risk indicator. In this study, a robust framework to execute FSI simulations based on time-resolved three-dimensional ultrasound (3D+t US) data was obtained and employed on a data set of 30 AAA patients. Furthermore, the effect of including a pre-stress estimation (PSE) to obtain the stresses present in the measured geometry was evaluated. The established workflow uses the patient-specific 3D+t US-based segmentation and brachial blood pressure as input to generate meshes and boundary conditions for the FSI simulations. The 3D+t US-based FSI framework was successfully employed on an extensive set of AAA patient data. Omitting the pre-stress results in increased displacements, decreased wall stresses, and deviating time-averaged wall shear stress and oscillatory shear index patterns. These results underline the importance of incorporating pre-stress in FSI simulations. After validation, the presented framework provides an important tool for personalized modeling and longitudinal studies on AAA growth and rupture risk.

Keywords: abdominal aortic aneurysms; fluid-structure interaction modeling; hemodynamics; patient-specific; pre-stress estimation; rupture risk; wall mechanics.